The FDA received nearly 60 reports of anaplastic large cell lymphoma, or ALCL, from women who had breast implants. The cancer generally formed around the shell of the implant, according to the reports.

ALCL, a rare and aggressive type of lymphoma, makes up only about 3 percent of all lymphomas in adults, according to the Lymphoma Research Foundation.

"If you look overall [at the likelihood of ALCL] for women who get these implants it is very, very rare," said Dr. Jasmine Zain, a lymphoma specialist who directs the bone marrow transplant program at New York University Cancer Institute.

Breast implants are most often used for cosmetic enhancement. About 350,000 women have had elective breast implantation, according to the American Society of Plastic Surgeons.

But many medical experts recommend breast augmentation as a reconstruction method for many women who have undergone a mastectomy. Around 57,000 women have undergone reconstructive breast implantation, according to the American Society of Plastic Surgeons.

Previous studies have suggested ALCL is more common in women with implants. Zain said she has seen a few cases of ALCL among patients who received silicone breast implants, suggesting that there may have been a link.

In fact, for decades many experts, including Dr. Michael Harbut, director of the environmental cancer program and the Karmanos Cancer Institute in Detroit, Mich., warned of potential harmful chemicals in breast implants.

"I'm angry," said Harbut. "I think the collective IQ of those at FDA to look into this sooner is equivalent to the temperature of the Arctic."

Breast Implants Linked to Rare Cancer

Harbut petitioned the FDA 11 years ago, warning about the potential link between cancer and toxins found in the gel and shell of breast implants.

"The popular press was reporting it was safe but it was going against every bit of my training," said Harbut. "You can't expose those to a known carcinogen and not think someone's going to get cancer."

Harbut's petition came after another filed by the watchdog group Public Citizen, nearly two decades ago.

"Animal evidence of carcinogenicity, especially with the highly malignant tumors found in these studies, should be taken more seriously than the leadership in the FDA has done over the past two decades," said Sidney Wolfe, director of Public Citizen's Health Research Group.

Still, since the risk of ALCL is relatively small, experts said women who already have implants should not worry about this form of cancer.

"Although they say the risk may be increased 18 times, that is still a very small number of women that are affected, given the large population that have received implants," said Dr. Len Licthenfeld, deputy chief medical officer of the American Cancer Society.

"Women with implants who are concerned should know this is not a subtle finding," said Dr. Phil Haeck, president of the American Society of Plastic Surgeons.

Women who were diagnosed with ALCL experienced abnormal pain and breast swelling, said Haeck.

The agency is not recommending that women with otherwise normal symptoms after an implant should have their implants removed, according to Dr. William Maisel, chief scientist and deputy director for science in FDA's center for devices and radiological health.

American Society of Plastic Surgeons and the FDA will create a registry to monitor breast implants and examine reported cases. The agency requested that doctors report any ALCL cases they may have seen.

Breast Implants Linked to Rare Cancer

The FDA also says it will urge breast implant manufacturers in coming months to update their product labeling materials for patients and health care professionals to highlight the potential risk.

"We're excited to let the public know we're monitoring the situation," said Haeck. "What we don't want to cause is panic in the streets."

However, many experts said while registry and labeling are small steps forward, the FDA should independently review all potential harms associated with breast implants.

"There should be an honest effort to look into the harms breast implants could cause, and it should be irrespective of plastic surgeons who potentially stand to gain based on the outcome," said Harbut. "That's like the chickens asking the foxes to keep track of the eggs."